Circuit-closing device for burglar-alarms



(No Model.

B. E. WILSON. CIRCUIT CLOSING DEVICE FOR BURGLAR ALARMS.

No. 595,842. Patented Dec. 21,1897.

UNITED STATES ATENT OFFICE.

ELMER E. \VlLSO-N, OF BLACIUVOOD, NEW JERSEY, ASSIGNOR OE ONE-HALF TO PARTRICK & CARTER. 00., OF PHILADELPHIA, PENNSYLVANIA.

ClRCUlT-CLOSING DEVECE FGR BURGLAR -ALARMS.

SPECIFICATION forming part of Letters Patent No. 595,842, dated December 7- Application filed August 18, 1897. Serial No. 648,670. (No model.)

T0 at whom it may concern.-

Be it known that I, ELMER E. lVILsON, a citizen of the United States,residin g at Blackwood, in the county of Camden, State of New Jersey, have invented a new and useful Improvement in \Vindow-Springs or Circuit- Olosing Devices for Burglar-Alarms, which improvement is fully set forth in the following specification and accompanying drawing.

My invention consists of an improved construction of window-spring adapted to allow a window to be left open at any desired height for purposes of ventilation, &c., in which after the alarm has been set or the electricity turned on the window cannot be further opened without sounding an alarm, all necessity for cutting the window-sash being also obviated, since the mechanism is located in a side of the window-frame.

It further consists of novel details of construction, all as will be hereinafter fully set forth, and particularly pointed out in the claim.

The figure represents a side elevation, partly in section, of a burglar-alarm embodying my invention and a portion of a window sash and frame to which the same is applicable.

Referring to the drawing, A designates a window-sash, the same being readily movable in the frame or casing B, one side of which has a recess (J therein, the walls of said recess having secured thereto a plate D, which has an opening E therein, through which extends the cam F, the latter being mounted on the spring or resilient arm G, and said cam and spring being a suitable conductor of electricity.

G designates a contact which is in the present instance of angular shape and has one limb secured to the plate D, said contact being properly insulated therefrom by the insulation H and being in the present instance held in position by the screw or fastening device J, from which the conductor K leads to a binding-post of the electric bell or alarm L, the latter having the conductor M leading from its other binding-post to a binding-post of the battery N or other source of electrical energy, said battery having a wire P leading therefrom to the screw Q, which serves in the present instance to hold the plate D and spring G in assembled position.

The operation is as follows: The cam F is normally held in contact with the sash by means of the spring G, thereby causing said cam to rise and fall with the movement of the sash, whereby the upper portion of the cam will be caused to strike the contact G, as indicated in dotted lines, thereby completing the circuit, the latter being broken when said cam falls away or assumes the position seen in full lines.

To set'the alarm, the electrical connections are broken and the window is then raised to the desired height and slightly lowered,which causes the cam to fall away from the contact G. The proper electrical connections are next made or a current is turned on, whereupon it will be seen that it will be impossible to raise the sash without carrying the cam F upwardly into the position seen in dotted lines, in which the circuit iscompleted and the alarm L sounded.

It will of course be evident that the cam E can be made of different shapes from that shown and that the spring D can be otherwise located or attached thereto, it being especially noted that the cam must contact with the sash in such a manner that it rises and falls with the movement thereof, whereby the circuit is made and broken in the manner described.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

In a window-spring or circuit-closing device for burglar-alarms, a plate having an opening therein, a spring secured at one end to said plate, a cam pivoted to the other end of said spring and projecting through said opening, a contact-piece having one limb secured to, but electrically insulated from said plate and its other limb adapted to .be in contact with the said cam, when the latter is raised by an upward movement of a sash, and an electric circuit having an alarm therein and connections with said contact piece and plate.

ELMER E. WILSON.

With esses:

Joan A. Wrnnunsnmn, WM. 0. Wmonnsnmn. 

